Randy, if you don't test phosphate when do you replace the gfo? I keep my reactor running probably long after the gfo is exhausted, but I only change it when my phosphates creep above 0.03 (hanna ultra low). Seems expensive to swap it out on a regular basis if it's not reached capacity.
Guesswork, combined with laziness. It is likely always depleted before I get to it. How long between glass scrapings are needed is a potential indication, but mine usually needs it in 24-48 h regardless of new vs old GFO.
That's an advantage of having many different phosphate export methods as I do since when one stops (like GFO being depleted), the others are still functioning and may take up at least some of the slack.
Guesswork, combined with laziness. It is likely always depleted before I get to it. How long between glass scrapings are needed is a potential indication, but mine usually needs it in 24-48 h regardless of new vs old GFO.
That's an advantage of having many different phosphate export methods as I do since when one stops (like GFO being depleted), the others are still functioning and may take up at least some of the slack.
